DE1238824B - Ignition system for the large-area ignition of propellant charges and / or drive charges - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

SCHES

PATENT OFFICE

EDITORIAL

Int. CL:

C06d

German KL: 78 d - l / W

Number: 1 238 824

File number: P 36049 VI b / 78 d

Filing date: February 11, 1965

Opened on: April 13, 1967

There are basically several possibilities for igniting propellant charges and charges. Intended to z. B. in a rocket engine or an artillery shell very quickly as much as possible of a charge are ignited, an ignition system is suitable for this, which is exactly in a longitudinal direction of the Charge extending recess fits. The known ignition systems had certain disadvantages, such as Inadmissibility, d. That is, the ignition rod was explosive, or the detonation did not occur with an appropriate one Speed so that the range and power of the grenade or the engine are not perfect was; other disadvantages were a lack of safety in handling and storage, high costs, excessive weight of the ignition system or ignition system along with the required ignition means and difficulty in actuation by means such as a flame or a Spark.

Fuses with a core of mixtures of 15 to 80% crystalline, highly explosive substances, one Oxidant and a fuel in a metal sleeve with a charge of 0.42 to 4.2 g per running meters are known.

U.S. Patent 2,959,001 discloses the use of a combination of a shaped charge an ignitable metal, e.g. B. aluminum, known. This can be in the form of a metallic coating the explosive as metal wire or metal powder, which is around or in the immediate vicinity of the explosive is distributed. However, it can also be an easily destructible metal lining for the soul be of a shaped charge. When the formed charge detonates, a jet of hot is created Gas and molten or vaporized metal, which at great speed lead to the ignition of the Explosives. Such an ignition system is expensive, not very safe and to use leads to greater destruction than when using a fuse, which is generally adjacent to the Propellant charge is arranged, whereas a shaped charge is forced from at least part of the The propellant charge is removed. After all, shaped charges must necessarily be more explosive and therefore require more careful design and monitoring to avoid shattering and intrusion to avoid in the explosives.

The invention thus brings an ignition system for the large-area ignition of propellant charges or propellant charges, especially long-arranged, elongated hooves where at zuiammeTrnT ~ cTem initiererrden ~ the detonation shock of the detonator heated, ignition system for large-area ignition of
Propellant charges and / or propellant charges

Applicant:

E. I. du Pont de Nemours and Company,

Wilmington, Del. (V. St. A.)

Representative:

Dr.-Ing. F. Wuesthoff, Dipl.-Ing. G. Pulse
and Dr. E. Frhr. v. Pechmann, patent attorneys,
Munich 9, Schweigerstr. 2

Named as inventor:

William Earle Schulz, Wenonah, N. J. (V. St. A.)

Claimed priority:

V. St. v. America 11 February 1964

(343 994),

dated September 1, 1964

(393 561)

Vaporized and / or ignited aluminum particles are brought into action on the surface of the propellant charge, and is characterized by the use of a detonation fuse, which is known per se, the explosive core of which, however, consists of a mixture of 50 to 95% lead azide of very high purity and 50 to 5% ₀ consists of finely divided aluminum and contains at least 0.05 g of lead azide per running meter.

The lead azide must have a very high purity; H. about 98.5 percent by weight (preferably RD-1333- or RD-1343 lead azide as described in Encyclopedia of Explosives and Related Items ", Vol. 1, Ed. Picatinny Arsenal, Dover, N. J., pp. A 557 to A 563).

The aluminum can range from powder-fine, i.e. around 1 μ, to coarse-grained, such as around 100 μ. be e.g. B. ground, comminuted pellets, turnings, sawdust and wood shavings, flakes. Aluminum powder of the type suitable for riveting (e.g. bulk density 0.76 to 0.88 g / cm ³ ; grain size: 100% <0.295mm, 80 to 90 ° / ₀ <0.175 mm, 60 to 70 ° / ₀ <0.147 mm, 2% <0.074 mm, is preferred, but the aluminum can also be in another fine form, e.g. granulated, atomized and / or flaky.

The amount and charge of the components in the mixture depend on several factors. The ignition

709 549/135

! 238 248

3 4

firing systems with a higher percentage of free shots with flammable cartridges, äfee

Its aluminum is usually less than that of fuses and grenades. Usual ignition masses, such as ScfawarzT

systems with a lower percentage, e.g. B. 10 to 25% powder and those with boron and potassium nitrate " ¹ O ^ Ar

A preferred mixture contains about 60 ° / ₀ lead azide silicon, potassium nitrate, activated charcoal and ferric oxide,

and 40% aluminum if the ignition system is e.g. B. 5 ignite largely at the speed of the

for artillery ammunition that burns without residue and detonation fuse z. B. about 1800 to 3000 m / sec.

Smoke bombs should be used. When high after ignition of the ignition system, the plant itself

Ignition speed with easily igniting fuels pulse with extremely high speed, e.g. B. about

is required, a high proportion of 1800 to 5000 m / sec is used over the entire fuse and

of lead azide, while one continues for more difficult igniting io of the charge attached to it, so that it becomes one

Fuels uses a lower proportion. With largely simultaneous burning of the entire

given distribution in the mixture is the speed of the inner surface of the load,

The speed of the propagation of the ignition pulse is all the less. The invention is illustrated with the aid of the drawings

the lower the lead azide content. Explained by increasing the.

Distribution, d. H. the charge of the ignition system with the 15 F i g. 1 shows a section through an inventive

Mixture, the speed increases. For the appropriate ignition system, and

For most purposes, the charge on the F i g exceeds it. 2 to 6 are sections through propellant charges with the ignition system of a mixture not 10.5 g per running ignition system according to the invention.
Meter; for a non-violent, non-explosive ignition in F i g. 1 is a detonation fuse 5 with the lead azide charge is preferably 0.21 to 20 of a ductile metal sleeve 1 and a core 2 in the form of 4.2 g per running meter, at least 0.105 g per running meter of a mixture of lead azide and aluminum. Higher charges placed on the ignition system.

are used, but usually exceed the standard. 2 is a common, tubular, on one

did not borrow about 42 grams per linear meter. In the case of charges, the housing 3 of an engine is closed at the end

g less than about 0,105 per meter is shown 25 which is fed to a nozzle 3 A.

suitable and reliable ignition of the main charge

not assured. Propellant 4 with a central cavity in which

The sleeve preferably consists of a thick-axially detonation fuse 5 extending over the entire walled, ductile metal, for example lead, a length of lead; It is made of alloy or aluminum by washers 6, so that it is held in place after loading 30, so that an air space 7 with the explosive core made of a mixture of lead between the fuse 5 and the propellant 4 azide and the fine aluminum by pulling, stretching. At one end of the fuse 5, or rollers can be pulled out uniformly, there is an electrical initiator 8 with power supply lines 9, largely down to the desired distribution. from a power source not shown.
The metal should not be used with any constituent of the mixture. 3, the arrangement is largely similar to that under the conditions to be expected for storage in FIG. 2, however, the fuse 5 and handling is responsive. Lead is preferred because it is wound in a helical shape on a mandrel 10, and small particles are formed during the detonation, which can indeed evaporate at a distance from the propellant charge 4. For high levels, so that in general only one security is an electrical or non-electrical small amount of one unwanted residue 4 ° detonator 8 for the ignition of both ends of the ignition remains. These small pieces of metal seem to be 5 used. Between each winding of an adjacent surface of the propellant charge to scrub detonating cord 5, a distance is provided in order to clean it in and out, so that the ignition of skipping and consequently a transverse propagation of the moist or otherwise impeded propellant impulse over the windings is to be prevented .
Sets and charges is enabled. 45 According to Fig. 4 direct ignition of the propellant

In general, the thickness of the sleeve is roughly equal to that obtained by putting the fuse through it

the diameter of the ignition system. If less, several separate, lined up at equal intervals

Charge and a low proportion of lead azide can cause propellants through their lengthways

generally results in a thinner sleeve than with higher bores. You can optionally have a

Charge can be used. So z. B. a weight 50 flexible line or a cable of suitable

the lead sleeve of about 9.84 g per running meter of material, e.g. B. nylon, sisal or hemp, in one

with a core of 0.21 g per running meter to a hole parallel to and close to the hole for the

complete shattering of the case and a detonating cord, provided these are not detrimental

reliable ignition of the propellant charge. Effects on the burning properties of the propellant

The ignition system according to the invention is applied to the usual 55.

Way operated, e.g. B. by an electric igniter, in a similar way one can have a direct or

a crimped bridge glow igniter, an exploding semi-direct ignition of the propellant can be achieved by

bridging wire, a spark igniter, or a man winding or looping the fuse in the

usual percussion fuse. The surface of the propellant according to the invention provides or the ignition

The ignition system can also be used in conjunction with a 60 cord only in the immediate vicinity of the

more easily ignitable compared to the main charge, d. H. Plating arranges.

more flame-sensitive ignition material in the form of an according to F i g. 5 is the fuse inside

Coating or a column can be applied. An ignition layer 12 on the surface of the driving

Ignition system in the form of detonation fuse set 4, which achieves semi-direct ignition

accelerates the normally low burn-off rate.

speed of such ignition masses and loading F i g. 6 shows an artillery shell, the

This also accelerates the ignition of the propellant. Detonating cord 4 in the longitudinal hole of the charge 4,

This is especially true when igniting artillery, for example. B. smokeless powder is located.

The fuse 5 contacts an ignition layer 12 which covers the wall of the bore.

The ignition system according to the invention can also be used in connection with z. B. basket-like detonators, finally also z. For example, for delivering gas propellant e l 5 in auxiliary power unit s to E n ergieerzeugung, barren to perforation of oil producing wells, cannons and smoke bombs to ignite for A rtiller iegeschutze NCT u ^ MOE rSERT by cartridges activated VorricEtungen etc.

Compared to the known mixtures of highly explosive substance, oxidizing agent and fuel it is very surprising that the presence of a chemical oxidizer is below normal atmospheric conditions has proven unnecessary, with a view to the inclusion of the Detonating cord within a cavity in the propellant charge; apparently the atmospheric oxygen is enough for a reliable detonation.

The invention is explained in more detail by means of the following examples. All parts and percentages are parts and percentages by weight unless otherwise specified.

example 1

By blending 60% lead azide high purity and 40% for riveting suitable aluminum and largely complete by moistening with a l% ig ^en solution of Pyronitrocellulose in butyl acetate (50 g mixture per 10 cm ³ solution), sieving through a screen with a clear mesh width 0.351 mm , Drying for 8 hours at 49 ° C., cooling and sieving through a sieve with a clear mesh size of 0.589 mm, a mixture with a loading density of about 1.1 g / cm ^{3 was} produced. 13.2 g of this mixture was introduced into a lead pipe (48.26 cm length, 0.584 cm inside diameter, 1.27 cm outside diameter) with shaking and drawn to an outside diameter of 0.139 cm. Load weight: 0.42 g per running meter. A 20.32 cm long piece was placed axially into a cardboard tube (0.95 cm inner diameter, 2.54 cm long) and the annulus around the fuse was filled with loose black powder. If the fuse was only ignited electrically at one end, it detonated at a speed of 2522 m / sec and ignited the entire powder charge largely at the same time.

Another portion of the tube was made to have an outside diameter of 0.127 cm and a loading weight drawn from 0.34 g / m; Detonation speed: 2558 m / sec. Again, that took place largely simultaneous ignition of the powder.

Another portion of the tube was made to have an outside diameter of 0.114 cm and a loading weight drawn from 0.2739 g / m; Detonation speed: 2230 m / sec, perfect ignition.

Example 2

The lead azide-aluminum mixture according to Example 1 was used to make various detonating cords in lead sleeves Made with an outer diameter of 0.792 cm and a length of 1.52 m, to an outer diameter of 0.185 cm drop forged and then drawn further until you get the ones listed in the table below Load weights received. Ignition with an electrical initiator with a basic charge of 0.096 g Contained lead azide.

Charge of the soul Detonation velocity (g per running meter) (m / sec) 0.235 2573 0.358 3163 0.279 2821 0.281 2749 0.302 2848

Example 3

By essentially following the procedure of Example 1, an outside diameter fuse was prepared from 0.139 cm; the core was a mixture of lead azide and aluminum in a ratio of 80:20 with a load weight of 0.52 g per running meter. It became one through a central core Smoke bomb drawn, with an ignition mixture arranged around the fuse, the 26% silicon, Contained 35% potassium nitrate, 4% activated carbon, 22% black iron oxide and 13% aluminum, granulated with a solution of 4 parts of nitrocellulose in 96 parts of acetone. Detonation velocity the cord: 3618 m / sec; the smoke bomb was detonated largely at the same time.

It has also been found that the ignition system according to the invention against ordinary shock and stray electrical currents are insensitive and difficult to ignite from the side.

Claims (1)

Claim: Ignition system for large-area ignition of propellant charges and / or propellant charges, especially in elongated cavities arranged therein, together with the initiating detonation burst an igniter heated, vaporized and / or ignited aluminum particles on the Propellant surface are brought into action, characterized by the known use of a detonation fuse, but its explosive soul a mixture of 50 to 95% lead azide of very high purity and 5 to 50% finely divided Aluminum and which contains at least 0.05 g lead azide per running meter. Considered publications:
French Patent No. 1,336,958;
U.S. Patent Nos. 2,959,001, 2,974,596. 1 sheet of drawings 709 549/135 4.67 © Bundesdruckerei Berlin